This study investigated the preliminary phytochemical composition of the chloroform extract from the leaves of lemon verbena (Aloysia citrodora Paláu; Verbenaceae) and evaluated the insecticidal, herbicidal, and toxicological activities of its extracts, as well as its essential oil. The toxicity assays using the Artemia spp. model indicated slight to moderate toxicity. Some extracts exhibited herbicidal activity at high concentrations, while promoting growth at lower concentrations. In insecticidal tests against the fruit fly Drosophila melanogaster, no significant mortality was observed; however, the methanolic extract showed approximately 85
En este artículo, propongo considerar problemas filosóficos que emergen a partir de la unificación de la teoría general de la relatividad y la mecánica cuántica. Dichos problemas, aunque relativos a los preguntas puramente técnicas de las matemáticas involucradas en ellas, conciernen a la interpretación y alcance de las reglas matemáticas y son evidencia de la siguiente tesis: la física del siglo XXI es testigo de que las constricciones lógicas y matemáticas de las teorías tienen prioridad sobre sus aplicaciones experimentales. Además, propongo que constricciones teóricas unidas a nuevos descubrimientos pueden aclarar estos problemas pero sin pretender una reducción definitiva.
Introduction: Temporomandibular disorders (TMD) are a group of conditions that affect the temporomandibular joint (TMJ) and the muscles that control jaw movement. These disorders are characterized by specific symptoms and signs. Material and methods: This is a cross-sectional study. Fifty university students participated, and temporomandibular dysfunction (TMD) was assessed using the Fonseca Anamnestic Index and associated with signs and symptoms. The Kolmogorov-Smirnov (K-S) test was applied to assess data normality, along with the X2 test and Mann-Whitney U test. SPSS version 27 software was used. Results: Twenty-one men (42%) and 29 women (58.9%) were included. TMD had a frequency of 58% in the university students analyzed. Severe TMD was associated with soft chewing (p=0.002). Moderate TMD was associated with previous physiotherapy (p=0.036), malocclusion (p=0.031), and hard chewing (p=0.042). Symptoms associated with severe TMD were nocturnal bruxism (p=0.000), morning stiffness (p=0.002), pain on opening (p=0.000), and vertigo (p=0.000). Symptoms associated with moderate TMD included jaw stiffness (p=0.039), muscle tension without tooth clenching (p=0.015), TMJ pain (p=0.004), and tearing (p=0.000). And at a mild level with headache (p=0.001) and tinnitus (p=0.003). Conclusions: College students with moderate and severe TMD showed a greater association of signs and symptoms, significantly impacting their daily lives.
Uno de los problemas que conciernen tanto a filósofos como a historiadores podría formularse de esta manera: ¿cuál es nuestra relación con la historia? Pero la tarea del filósofo y la del historiador ante este problema es diferente. En este trabajo nos proponemos desarrollar una serie de intuiciones acerca de la experiencia de la historia desde un enfoque fenomenológico. ¿Cómo es nuestra experiencia de la historia? Lo que vamos a defender es que la experiencia de la historia forma parte de nuestro modo de ser y que nuestra vida cotidiana se despliega en un horizonte histórico. Este horizonte es intersubjetivo, es decir, social, y en él se entrelazan diversas generaciones que se dejan motivar e influir unas por otras. Defendemos que el estudio de la historia no tiene como finalidad comprender el pasado, sino el presente, y para ello las narrativas ocupan un lugar central.
Praziquantel (PZQ) has been used for over four decades as a first-line monotherapy against schistosomiasis, demonstrating high clinical efficacy. However, scientific evidence suggests reduced sensitivity in certain parasite species, highlighting the need for a deeper understanding of its molecular mechanism of action and its intrinsic structural limitations. In this study, a computational screening analysis was performed to identify the structural determinants that define the lead optimization space for PZQ. Additionally, the viability of PZQ as a lead compound in the rational design of new antiparasitic agents was evaluated by analyzing derivatives previously reported in the scientific literature. Two hundred PZQ derivatives with reported in vitro biological activity data were compiled. From these, eight representative molecules were selected for structure-activity relationship (SAR) analysis and molecular docking studies. The set included compounds without antischistosomal activity, as well as those with activity similar to, equal to, or superior to PZQ. The results revealed that the stability of the Sm.TRP PZQ –ligand (PZQ and derivatives) complex depends on a cooperative equilibrium between critical hydrogen bonding and hydrophobic interactions, which ensure precise conformational orientation within the Sm.TRP PZQ binding site. Alterations in these properties significantly compromise biological activity, thus restricting the chemical space for optimization. Collectively, these findings indicate that PZQ represents an exceptionally well-balanced anti-schistosomal scaffold, whose structural characteristics suggest a conformational equilibrium that is difficult to surpass, explaining why extensive optimization efforts have not yielded superior clinical alternatives.
